I am currently using ubuntu 11.10, it had deja dup pre-installed on the system, its a backup and restore utility, but it doesn't support snapshots. There is no such tool for snapshotting in ubuntu. I know that taking snapshots requires Filesystem support, are there any other problems associated ? I would like to know this.

I want to write a system backup and restore utility which could have continuous backup so I want to know if any already exists.